1. Field of the Invention
The present invention relates to Bluetooth communication. More particularly, the invention relates to a Bluetooth-enabled mobile terminal and fast device connection method thereof that is capable of reducing device connection latency and power consumption.
2. Description of the Related Art
With the increasing interest in wireless personal area networks, various short range wireless communication technologies have been developed and commercialized. Bluetooth is one of the radio-based communication standards. Bluetooth operates in an open 2.4 GHz Industrial, Scientific, and Medical (ISM) band and offers a distance range from 10 to 100 meters with the data rate from 1 to 2 megabits per second. Because of this low power consumption feature, Bluetooth modules are increasingly applied to a wide variety of commercial and industrial fields.
Typically, Bluetooth establishes a radio link between two Bluetooth-enabled devices through a series of procedures: a connection inquiry procedure in which the device intended to play role of master broadcasts an Inquiry message, receives Inquiry Response (Inquiry_res) messages transmitted by the devices dedicated to play rolls of slave, transmits a Remote Name Request message to each of the devices, and receives Remote Name Request Response (Remote Name Request_res) messages, a paging procedure in which the master device transmits a Page message to a target device and receives a Page Response (Page_res) message from the target device, and a pairing procedure in which the master device transmits a Pairing message to the target device and receives a Pairing Response (Pairing_res) message.
In the connection Inquiry procedure, the master device searches the slave devices randomly. Accordingly, when the slave devices are located at a threshold distance or a relatively far distance, the master device is likely to fail to receive the Remote Name Response message or receive the Remote Name Response message with several-second delay.
In the case of no receipt of the Remote Name Response message, the master device retransmits the Remote Name Request message up to three times, resulting in a delay of response time.
Also, the conventional Bluetooth device is configured to transmit the Inquiry and Remote Name Request messages at a uniform transmission power, i.e. a fixed Power Control Level (PCL), for searching for the devices located far away, thereby wasting transmission power.